Liquid cooled frictional weight lowering device



United States Patent lnventors Appl. No.

Filed Patented Assignee Jimmie A. Chezem Falls Church;

Robert E, Bendl, Denbigh, Va.

Dec. 26, 1963 Dec. 29, 1970 United States of America, as represented by the Secretary of the Army LIQUID COOLED FRICTIONAL WEIGHT LOWERING DEVICE 12 Claims, 6 Drawing Figs.

US. Cl 188/6S.4; 182/5,182/72.182/193;188/264 Int. Cl B65h 59/14 Field of Search 188/65. 1,

References Cited UNITED STATES PATENTS 10/1890 Zein et a1 188/65.3 6/1916 Lyna..... l88/65.5 3/1922 Evans.... 294/12 4/1895 Gerald 188/65.3 6/1921 Butterfield l88/65.4 5/1935 Reith 294/12 4/1945 Pierce l88/264(.2) 11/1965 Holkesvick 188/65.4

Primary Examiner-George E. A. Halvosa Attorneys-Harry M. Saragovitz, Edward J. Kelly, Herbert Berl and James W. Colvin ABSTRACT: This invention relates to weight-lowering devices and particularly to a device for lowering a person along a depending line or rope and controlling the rate of descent by a snubbing action of the line on the device. Means to cool the device are contained therein.

' PAIENTEU, [15:29 I976 I INVENTDRS, JIMMIE AJIHEZEM ROBERT E. BEN DL PATENTED UEBZ 919m SHEET 3 0P3 INVENTOKS JIMM IE AJLHEZEM ROBERT E. BENDL BYJX/ Olav-ah g lw fip dale Z Manam LIQUID coouan FRICTIONAL WEIGHTILOWERING DEVICE The invention described herein maybe manufactured and used by or for the Government for governmental purposes without the payment to us of any royalty thereon.

Weight lowering devices, in simplified form, have been previously built and tested and have been found to operate successfully with light weights, very slow rates of descent, and nonrepetitive operation. When it was attempted to adapt such devices to military use, such as the rapid deployment of combat troops from a hovering helicopter, such devices were found to be entirely inadequate. They not only lacked the necessary strength, as evidenced by breaking of hooks and eye fonnations, and failed to provide the desired-rate of descent for fully equipped combat troops, but overheated to such an extent that they charred the associated rope and burned the hands of the troops using them. 3

In view of the above described situation,'it is-among the objects of the present invention to provide a weight-lowering device of adequate strength such that it can be used by fully equipped combat troops without danger of structural failure.

A further object resides in the provision of a line carried weight-lowering device having heat dissipating means of an efficiency such that the device will not seriouslyoverheat when used to deploy fully equipped combat troops from a hovering helicopter at a rapid rate of descent and in rapid succession from altitudes up to 200 feet. v

A still further object resides in the provision of a weightlowering device of the character indicated which is so shielded that it can be grasped by the bare hands during a descent without material discomfort.

An additional object resides in the provision of a weightlowering device of the character'indicated which is extremely simple and economical in construction, can be easily serviced and repaired in the field,can be used many times without serious wear, and can be stored or left in the field for long periods without corrosion or other material deterioration.

' Other objects and advantages will become apparent from a consideration of the following description and the appended claims in conjunction with the accompanying drawings wherein:

, FIG. l-is a diagrammatic illustration of the use of the device ofthe invention;

FIG. 2 is a side elevational view of a weight-lowering device illustrative of the invention, a center portion of the device being broken away for convenience in illustration;

FIG. 3 is a d side elevational view of the weight-lowering device with the shield or cover removed and a line or rope shown applied to the device;

FIG. 4 is an end view on a reduced s'caleof the upper end of the device with the upper end closure cap removed; I

FIG. 5 is an end view on a reduced scale of the lower end of the device as illustrated in FIG. 6 and I- FIG. 6 is a longitudinal cross-sectional view substantially on a plane indicated by the line 6-6 on FIG. 4.

With continued reference to the drawings and particularly to FIG. I, the numeral 10 generally designates a troop or personnel carrying helicopter such as might'be used by the Army to transport combat troops and deploy them onto a selected combat area. The Army has several types of such helicopters and the Navy also has several types of helicopters, some of which coincide with Army types. In the arrangement illustrated, the ingress and egress of personnel is through a side door which is in the fuselage of the helicopter and if combat troops are to be deployed from the helicopter while in hovering position they must emerge through thisdoor and be lowered safely to the ground. The numeral 12 designates a depending rope or line the upper end of which is secured to the helicopter at the bottom of the doorway 11 by a suitable bridle or harness 13. Several types of line have been tested but it has been found that a hard braided nylon line of 'the proper size provides the most desirable component'for this purpose since a nylon line has an amount of elasticity that will relieve a person being lowered along the line from major shocks in the event of sudden retardation of free-fall or sudden vertical movements of the supporting helicopter. The numeral 14 indicates a line-carriedlowering device such as illustrated in detail in FIGS. 2 through 6 inclusive, and to be later described,

and the numeral 15 indicates a person, such as a combat soldier being lowered from the helicopter to the ground for deployment in a combat area or for other purposes. The soldier is connected to the weight-lowering device 14 by a suitable harness 16, somewhat in the nature of a parachute harness, which surrounds and engages the body of the soldier'and has a hook for detachably connecting the harness to the lower end of the device 14. This hook is illustrated in FIG. 3 and indicated at Referring now to FIGS. 2 through 6- inclusive, the weight lowering device comprises a hollow core member, generally designated at 20, around which the line 12 is wrapped so that the rate of descent of the device is retarded by the snubbing action of the line 12. This core has top and bottom end portions 21 and 22 of cylindrical shape and a cylindrical intermediateportion 23, of less diameter than-but coaxial with the end portions, joining the two end portions. An integral eye formation 24 extends longitudinally from the-lower end portion 22 to provide an attachment for the harness hook I7 and the lower end portion is provided with longitudinal grooves 25 and 26 which the line 12 extends. I

The upper end portion 21 is longer than the lower end portion 22 and is hollow throughout its length. The intermediate portion 23 is also hollow throughout its length and this hollow or bore of the intermediate portion extends slightly into the I end portion 22, which is otherwise of solid construction. A

curved groove 28 extend longitudinally of the surface of the upper end portion 21 for the passage-of the line 12 past this end portion and this groove is carefully and accurately shaped to avoid any definite points of friction concentration between the line and sides of the groove as the weight lowering device moves along the line. I 1

As shown in FIG. 3 the line 12 is given two or three wraps or windings about the intermediate portion 23'of the core and with this arrangement and with the upper end of the line secured to an elevated object, such as the helicopter to, movement of the weight lowering device downthe line will be retarded by the friction between the line and thecore 20, this frictional snubbing of the device by the line'being regulated by pulling on the free portion of the line below the device. It is possible to entirely stop the descent of the device by a sufficient pull on the lower portion of the line. I I

As is readily apparent to anyone having training in physics, the descent slowing friction between the line and the core 20 of the device 10 generates a material .'amount of heat, the

amount of heat generated being affected by the rate and length of the descent and the amount ofthe weight lowered.

As a fully equipped combat soldieroften weighs well over 200 pounds, sometimes as much as 240 or ZSO-pounds, as the safe hovering level of the helicopterrnay be up to 200 feet above the ground depending upon weather conditions and ground obstructions and, as the rate of descent needs to be as rapid as safety to the personnel will permit inorder to deploy the entire complement of combat troops from helicopter in the least amount of time, it can be seen that sufficient heat will be generated by the device under these conditions to render the device entirely too hot to be grasped by the person using the device for descent, as shown in FIG 1. It has also been found, as has been explained above that "the temperature of the device may raise to a point where thenylon line is tions including temperatures below the freezing temperature of water, it is desirable to use a combination of water and a suitable antifreeze to maintain the device in effective conditionat all times. Since the line has only limited contact with the large upper end portion 21, this portion will normally remain cooler than the intermediate portion 23 where most of the friction generated heat is produced. It is, therefore, desirable to provide for circulation of the cooling liquid from the lower to the upper end of the device and return. This is accomplished by a circulation tube or conduit 30 which extends from the lower end of the bore in the intermediate portion 23 to near the upper end of the interior of the upper end portion 21, and a second tube or conduit 31 which extends from near the upper end of the upper end portion 21 through an apertured partition 32 which is located at the upper end of the intermediate portion 23 of the core. Since the liquid in the intermediate portion 23 becomes warmer than the liquid in the upper end portion 21, convection will cause the warmer water to rise through the tube 30 into the upper end of the end portion 21 and for the cooler water in this compartment to descend through the tube 31 into the interior of the intermediate portion 23.

The outer end of the upper end portion 21 is open, as indicated in FIGS. 4 and 6, and this open end is closed by a flat cap 34 detachably secured to the outer end of the portion 21 by suitable fasteners, such as the cap screws 35. A gasket 36 is interposed between the cap and the outer end of the core end portion 21 to provide a leakproof joint between the cap and the end of the core. The cap 34 is provided substantially cen trally thereof with a screw threaded opening 37 and a valve 38, FIG. 3 is threaded into this opening. This is a pressure relief valve which will permit vapor to escape from the hollow interior of the core if the cooling liquid is vaporized to a degree that sufficient pressure is built up to operate the valve. This valve can be removed from the cap 34 to clear the opening 37 for filling or refilling the interior of the core with cool ing liquid.

While the temperature at which the cooling liquid vaporizes is not high enough to damage the nylon line, it may still be high enough that the core of the device to control his rate of descent along the line 12. In order to maintain the outside temperature of the device at a value at which the device can be grasped with reasonable comfort, a cylindrical guard or shield 40 receives the core 20 of the device and preferably ex tends from near the lower end of the lower end portion 22 to the edge of the lower side of the cap 34, so that substantially the entire core of the device is inclosed. This cylindrical shield has an inside diameter substantially equal to the outside diameter of the end portions 21 and 22 of the core 20 and is held in position on the core by suitable means, such as a flange 41 on the lower end of the lower end portion 22 and a set screw 27. This shield is preferably thin-walled and formed ofa suitable material so that it will withstand the abuse to which the device is subjected in use and is also provided with a large number of perforations 42 which permit a free flow of air through the shield to convey heat away from the core 20 while, at the same time, maintaining the shield at a temperature at which it can be comfortably grasped.

The entire device is preferably formed of suitable lightweight, corrosion resistant material, such as aluminum or stainless steel, and is of rugged construction so that it will not be deformed or damaged by the loads imposed on it during use.

If there are a sufficient number of the weightdowering devices in the helicopter, an individual device may be used for lowering each soldier or other person from the helicopter and the devices are then stacked in a convenient location on the ground for later recovery. However, if there are an insufficient number of devices for providing an individual device for each person, the line 12 may be provided as a loop with both ends secured in the helicopter and its intermediate portion on or adjacent the ground rather than as a single depending line. With this latter arrangement, the weight-lowering device will remain on the line and can be recovered by a crew member of the helicopter pulling in the end of the line until the device is brought within reach and then replacing the device on the line for another descent. If desired, the device can be used to lower objects from an elevated support such as a hovering helicopter, the rate of descent in that case being controlled by a person on the ground applying a controlled force to the line below the device. a

While a preferred embodiment of tljie invention has been adapted to receive a body of cooling liquid, a cap detachably secured to and closing an open end of said core, and a shield of cylindrical shape receiving and detachably secured to said core. H

2. A weight-lowering device for use with a depending line or rope comprising a hollow core of cylindrical shape having end portions of larger diameter than the intermediate portion thereof, said end portions having line guiding grooves therein and said intermediate portion being adapted to receive wrappings of the associated line, said core being-hollow and adapted to receive a body of cooling liquid, an-eyelfolfmation extending longitudinally from one end of said core for the attachment of a harness thereto, and a shield of cylindrical shape receiving said core and having openings therein for the passage of ventilating air to and from said core.

3. A device for lowering a person or object along a line depending from an elevated support comprising a hollow elongated member having spaced apart end portions and an intermediate portion of smaller diameter than said end portions extending between and joining said end portions, said intermediate portion being adapted to receive one or more wrappings of an associated line and said end portions being .effective to retain the line wrappings on said intermediate portion one of said end portions being normally the upper and the other the lower end portion, an eye formation extending from said lower end portion for attaching a person or object to the device, a body of heat absorbing liquid in said hollow member, and tubes supported in said hollow member to extend longitudinally thereof for providing a circulation of liquid from the lower end of said intermediate portion into said upper end portion and from said upper end portion into said intermediate portion when said liquid is heated.

4. A descent control device for frictional sliding engagement with a length of rope, comprising: a body member of heatconducting material having an elongated shaft portion with an outer surface of a length to receive varying turns of rope thereabout; a hub portion adjacent each end of the shaft portion; at least one generally axially extending passageway with an inner surface in each hub portion, said passageway being of a size to slidably receive the length of rope; attachment means connected to the body member; container means for receiving a body of fluid having a predetermined vaporization temperature positioned in heat-receiving relationship with said body member to receive therefrom heat produced therein by the sliding frictional engagement of a rope with the body member; and means in communication with the interior of the container means for venting to the atmosphere any vapor produced from said fluid by the heat of friction generated in the body member by the sliding'rope.

5. A descent control device for frictional sliding engagement with a length of rope, comprising: a body member of heat-conducting material having an elongated shaft portion with an outer surface of a length to receive varying turns of rope thereabout; a hub portion adjacent each end of the shaft portion; at least one generally axially extending passageway with an inner surface in each hub portion, said passageway being of a ,size to slidably receive the length of rope; attachment means connected to the body member; container means for receiving a body of fluid having a predetermined vaporization temperature positioned in heat-receiving relationship with said body member to receive therefrom heat produced therein by the sliding frictional engagement of a rope with the body member; and open passage means between the interior of the container means and the atmosphere for venting to the atmosphere any vapor produced from said fluid by the heat of friction generated in the body member by the sliding rope.

6. A descent control device for frictional sliding engagement with a length of rope, comprising: a body member of heat-conducting material having an elongated shaft portion with an outer surface of a length to receive varying turns of rope thereabout; a hub portion adjacent each end of the shaft portion; at least one generally axially extending passageway with an inner surface in each hub portion, said passageway being of a size to slidably receive the length of rope; attachment means connected to the body member; an elongated cavity in said shaft portion of a size to receive a body of fluid having a predetermined vaporization temperature; and means in communication with the interior of the cavity for venting to the atmosphere any vapor produced from said fluid by the heat of friction generated in the body member by the sliding rope.

7. A descent control device for frictional sliding engagement with a length of rope, comprising: a body member of heat-conducting material having an elongated shaft portion with an outer surface of a length to receive varying turns of rope thereabout; a hub portion adjacent each end of the shaft portion; at least one generally axially-extending passageway with an inner surface in each hub portion, said passageway being of a size to slidably receive the length of rope; attachment means connected to the body member; an elongated cavity in said shaft portion of a size to receive a body of fluid having a predetermined vaporization temperature; a filling opening adjacent the upper end of the cavity; and a combination filling and vent plug removably mounted in said opening, said plug containing a passageway therethrough for venting to the atmosphere any vapor produced from said fluid by the heat of friction generated in the body member by the sliding rope.

8. A descent control device as set forth in claim 7 in which the passageway in the combination filling and vent plug is provided with a pressure responsive valve which remains closed until the vapor attains a predetermined value.

9. A descent control device for frictional sliding engagement with a length of rope, comprising: a body member of heat-conducting material having an elongated shaft portion with an outer surface of a length to receive varying turns of rope thereabout; a hub portion adjacent each end of the shaft portion; at least one generally axially'extending passageway with an inner surface in each hub portion,- said passageway being the inner surface of each passageway being substantially coextensive with the outer surface of the shaft portion; attachment means connected to the body member; an elongated cavity in the shaft portion of a size to receive a body of fluid having a predetermined vaporization temperature; means in communication with the interior of the cavity adjacent the upper end thereof for venting to the atmosphere any vapor produced from said fluid by the heat of friction generated in the body member by a sliding rope; a rigid sleeve member removably mounted on said body member in engagement with the hub portions thereof, said sleeve member containing means for controlling the flow of heat from said body member.

10. A descent control device as set forth in claim 9 in which the rigid sleeve member comprises a perforated tubular element.

11. A device for lowering a person along a line depending from an elevated attachment point comprising a unitary hollow core adapted to function in upright position with the associated line wrapped about the longitudinally intermediate portion thereof and the lower end thereof closed to constitute said hollow core a receptacle for cooling liquid, said core hav ing end portions of greater diameter than the intermediate portion and provided with longitudinal grooves for the passage ofthe line to and from said intermediate portion, a detachable cap covering the upper end of said hollow core, a cylindrical shield receiving said core with its end portions closely receiving the end portions of the core and its intermediate portion annularly spaced from the intermediate portion of the core to protect the hands of a user of the device from heat generated by friction of the line passing around and along the intermediate portion of the core, and an eye formation extending from the closed end of said core for supporting a person from the device.

12. The device as described in claim ll including a pressure relief valve secured in said cap to vent heat generated vapor from the interior of the core, said valve being removable from said cap to provide an aperture for supplying liquid to the receptacle provided by said hollow core. 

